block/noop-iosched.c

   1 /*
   2  * elevator noop
   3  */
   4 #include <linux/blkdev.h>
   5 #include <linux/elevator.h>
   6 #include <linux/bio.h>
   7 #include <linux/module.h>
   8 #include <linux/init.h>
   9
  10 static void elevator_noop_add_request(request_queue_t *q, struct request *rq)
  11 {
  12         rq->flags |= REQ_NOMERGE;
  13         elv_dispatch_add_tail(q, rq);
  14 }
  15
  16 static int elevator_noop_dispatch(request_queue_t *q, int force)
  17 {
  18         return 0;
  19 }
  20
  21 static struct elevator_type elevator_noop = {
  22         .ops = {
  23                 .elevator_dispatch_fn           = elevator_noop_dispatch,
  24                 .elevator_add_req_fn            = elevator_noop_add_request,
  25         },
  26         .elevator_name = "noop",
  27         .elevator_owner = THIS_MODULE,
  28 };
  29
  30 static int __init noop_init(void)
  31 {
  32         return elv_register(&elevator_noop);
  33 }
  34
  35 static void __exit noop_exit(void)
  36 {
  37         elv_unregister(&elevator_noop);
  38 }
  39
  40 module_init(noop_init);
  41 module_exit(noop_exit);
  42
  43
  44 MODULE_AUTHOR("Jens Axboe");
  45 MODULE_LICENSE("GPL");
  46 MODULE_DESCRIPTION("No-op IO scheduler");